The ladder stabilizing structure of the instant invention comprises an improvement over the ladder adjusting and stabilizing apparatus disclosed in my prior U.S. Pat. No. 3,933,221, issued Jan. 20, 1976. p The stabilizing structure of the instant invention is constructed in a manner whereby it may be more readily attached to an existing ladder and in a manner whereby a greater range of adjustment of the stabilizing structure and greater stabilizing effect on the associated ladder is provided. Further, the stabilizing structure is constructed in a manner whereby it may be more readily telescoped and folded into a fully collapsed position.